﻿Partial Public Class wfrmValidaEmail
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    End Sub

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
        If EmailAddressCheck(Me.TextBox1.Text) Then
            Me.lblOK.Text = "Opa!! esse e-mail é válido hein!"
        Else
            Me.lblOK.Text = "E-mail inválido!!"
        End If
        Me.lblOK.Visible = True
    End Sub

    Function EmailAddressCheck(ByVal emailAddress As String) As Boolean

        Dim pattern As String = "^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"
        Dim emailAddressMatch As Match = Regex.Match(emailAddress, pattern)
        If emailAddressMatch.Success Then
            EmailAddressCheck = True
        Else
            EmailAddressCheck = False
        End If

    End Function

End Class